Elastic-fluid turbine



0. JUNGGREN ELASTIC FLUID TURBINE May 6 1924.

Filed Dec. 5.

' Inventor! Oscar" -Jungg1-en byfi M J:

His Attor-hey.

Patented May 6, 1924.

UNITED STATES TI OSCAR JUNGGREN, OF SCHENEGTADY, NEW YORK, ASSIGNOB, TOGENEBAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELASTIC-FLUID TURBINE.

Application filed December 5, 1922. Serial No. 665,115.

T all whom it may concern.

Be it known that I, OSCAR JUNGGREN, a citizen of the United States, residing at Schenectady, in the county of Schenectady,

I State of New York, have invented certain new and useful Improvements in Elastic Fluid Turbines, of which the following is a specification.

The present invention relates to elastic 1 fluid turbines and especially to elastic fluid turbines of the axial flow impulse type.

In elastic fluid turbines of large sizes runnin at low vacua the quantity of elastic fluid to be handled in the low pressure end becomes very large so that a very large bucket area is required to handle it. In fact, the maximum capacity of a turbine for any given speed is always limited by the low pressure end of the machine, i. e. by the ability of the low pressure end of the machine to handle efliciently the elastic fluid. It is the common practice to obtain additional bucket area in the low pressure end of a turbine by increasing both the wheel diameter and the bucket length. However, the limit of wheeldiameter is soon reached because of the peripheral speed becoming excessive and the limit in bucket length is reached because of the inefliciency of very 30 long buckets, due to the fact that the tips travel at a much higher speed than the roots.

The object of my invention is to provide,

an improved turbine structure wherein I am enabled to use long buckets in an eflicient manner, and for a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the drawing, Fig. 1 is a sectional view of a turbine structure embodying my invention, and Figs. 2 and 3 are detail sectional views taken on lines 2-2 and 33, respec-.

tively, Fig. 1.

Referring to the drawings, 5 indicates the shaft of an elastic fluid turbine, 6 the shell, 7 the diaphragms, and 8' the bucket wheels carried by shaft 5. The diaphragms are supported by shell 6 and are provided with nozzles 9 and diaphragm packings 10. On the bucket wheels 8 are rows of buckets 11. Fig. 1 shows only a portion of the low pressure end of a turbine and the parts so far referred to are to be taken as typical of any suitable structure to which my invention may be applied. Now according to my in The elastic fluid from the preceding stage t and that taken from a stage or stages in advance of the preceding stage and which by-passesthe preceding stage, are applied to different radial portions of the bucket ring each being supplied to a portion or the bucket ring which is traveling at a velocity suited to the velocity of the elastic fluid. I thus obtain elastic fluid discharging from nozzles at a velocity suited to the velocity of the portion of the buckets upon which it acts. Either one or more stages may be by-pa-ssed and there may be one or more by-passes in connection with a single row of buckets, the particular arrangement depending uponthe difference in speed between the roots and tips of the bucketswhich make up the bucket ring. Viewed from another aspect, I provide a turbine stage having long buckets and supply elastic fluid to them partly from the preceding stage and partly from one or more stages in advance of the preceding stage. 1

Referring specifically tothe drawing, t indicates a turbine stage containing a wheel having long buckets. The radially inner portions of the buckets receive elastic fluid from the bucket wheel of the prewding stage B through nozzles B while the radial- 1y outer portions of the buckets receive elastic fluid from the stage A in advance of stage B, special nozzle A being provided for directing the elastic fluid from stage it to the bucket ring of stage C. By the arrangement a portion of the elastic fluid from stage A is by-passed around stage B and applied directly to the bucket ring of stage C. The arrangement is such that nozzeles B discharge elastic fluid at a velocity suited to the speed of the radially inner portion of the bucket ring in stage C and nozzles A discharge elastic fluid at a velocity suited to the speed of the radially outer portion of such'bucket ring. This gives a more uniform action on the buckets of stage C and a higher degree of eliiciencyv Any percentage of the total quantity of elastic fluid may be so by-passed as may be found desirable and while in the present instance only a single by-pass is illustrated,

it will be readily appreciated as already 'pointed out that more than one stage may be bypassed in accordance with the principle of my invention.

Viewed from still another aspect, it may be considered that stages A and C are normal or main stages, that is stages having buckets through which all the elastic fluid flows and that stage B is an auxiliary or supplement-ar Y stage introduced between stage and C and through which only the radially inner portion of the annular elastic fluid stream flows.

By utilizing my invention I am enabled to construct a turbine in whichall or any desired number of the wheels are of the same diameter and the inside portions of all or a. similar number of the diaphragms are of the same diameter. This. is of advantage in that it means that a large'number of the parts are alikej'and hene'efc'an be manufactured at a lower cost. Also since the wheelsare of small diameter the stresses in them will be low so they may takethe form of flat disks. With advantage, a wheel diameter suitable for the first stage wheel may be selected and all the remaining wheels then made of this samediameter, the required bucket area being obtained by increasing the lengths of the buckets. Such .a by-passing arrangement embodying my invention may be then utilized as meets the requirements-of the particular case.

In accordance with theprovisions of the patent statutes, 1 have described the principle of operation of my invention, together with the apparatus which I nowconsider to represent the best embodiment thereofibut I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried outzby other means.

What I claim as new and desire to secure by Letters Patent of the United States, 1s,-

1. In an elastic fluid turbine, a stage having long buckets, and means for supplying elastic fluid thereto independently from the preceding stage and from a stage in ad- Vance of the preceding stage.

2. In an elastic fluid turbine, a stagehaving long buckets, fluid-directing means for supplying elastic fluid from the preceding stage to the radially inner portion of said buckets, and fluid-directing means for supplying elastic fluid from a stage in advance of said preceding stage to the radially outer portion of said buckets.

3; In an elastic fluid turbine, a plurality of stagehaving wheels of the same diam eter and buckets which increasein length, and means for supplying elastic fluid to the buckets" of one stage independently from.

two .ormorelpreceding stages.

a. An elastic fiuid turbine having a plurality of successive stages through which all the elastic fluid passes, characterized by the fact that between certain of the stages there is interposed a. supplemental, stage the buckets or which arc-acted upon only by theradiallyinner portion-of the annular elastic fluid stream flow. I l

5. In an elastic fluid turbine, the combination with two adjacentstages one in advance of the other as regards the flow of? elastic fluid, of a stage interposed between said two adjacent stages and fluidwlirecting means for conveying elastic fluid from the radially inner portion of-the earlier stage through said interpo'sed stage to the later stage and. from the radially outer portion ofsaid earlierstage around said interposed stage to the later stage.

In witnesswhereof, Ilia-ye hereunto set myfhandithis 4th day of December, 1922.

,oscA Neennn. 

